In digitally based image capturing devices an image or “photograph” of an object is stored in a digital data format in the memory within, or coupled to, the image capturing device. A nonlimiting example of a image capturing device is the digital camera that captures still images and/or video images. Captured images are stored in a memory that resides within or is coupled to the digital camera.
Watermarking and other tampering detection techniques are known in the art for protecting the integrity of individual images. The watermarking and tamper detection techniques allow confirmation that the image has not been altered or otherwise tampered with.
However, groupings of images can be altered or otherwise tampered with. Potential alteration of a group of images includes the removal of one or more images from the group, the addition of one or more images to the group, and/or the replacement of one or more images of the group.
For example, a group of images may be captured by the police at a crime scene. During the investigation and/or trial, it would be very undesirable if one or more of the original images were “lost” from the group, if one or more images not from the original group of images were added to the group, or if one or more original images were replaced. If any such occurrence were to occur to the group of images, individual image watermarking might fail to detect added, missing or replaced images.
Another nonlimiting example includes electronic archiving of documents. For example, images of public records such as property assignment documents filed at a public office may be digitally copied and stored electronically. Thus, a group of images could establish a chain of title for the property. During a title search, it would be very undesirable if one or more of the images were “lost” from the group, if one or more images not from the group of images were added to the group, or if one or more images were altered. If any such occurrence were to occur to the group of original images, individual image watermarking techniques might fail to detect added, missing or replaced images.